A travel lift is sized by the hull, not by the number on the beam. The rated capacity has to cover the heaviest vessel with the slings in the positions the builder specifies; the beam height has to clear the hull and its keel; the sling length has to reach under the hull at the slipway; and the wheel loads have to suit the quay or hardstanding. A 300 t machine for a 45 m motor yacht is a different design from a 300 t machine for a catamaran of the same weight.
Travel lifts — also called boat hoists, yacht lifts or mobile boat hoists — are the standard way a marina or shipyard takes a vessel out of the water without a slipway cradle or a fixed crane. The machine drives over the moored or docked hull, lowers its slings into the water or around the hull, lifts, and carries the boat to a storage position on land.
That sequence looks simple, and it is the reason the machine is popular. It also hides the constraints: the hull is not a rigid box, the slings are the only connection, and the lift usually happens over water or over a slipway that was not designed for a 100 t wheel load.
How a travel lift works
The structure is a portal: two legs, a top beam, and a hoisting system that raises a set of slings. The machine drives over the vessel so the hull sits between the legs, the slings are positioned under the hull, and the hoist takes the weight. The vessel is then carried, suspended, to the wash pad, the storage blocks or the transport trailer.
- Slings, not a spreader. The hull is supported on wide webbing or on padded slings at positions chosen by the naval architect or the yard.
- Four to eight lifting points are common, depending on hull length, weight and shape. Each sling carries a share of the total, and that share is not equal in a hull that is heavier aft.
- The machine moves with the load suspended. Travel speed, braking and steering all act on a hull that is free to swing if the slings are not controlled.
- The set-down is part of the cycle. Blocks, cradle or trailer have to be positioned before the boat is lowered, and the slings have to be released without dragging on the hull.
The hull as a load
Every other lifting machine on this site carries a load that can be described by weight and dimensions. A hull cannot. What the travel lift needs to know is where the weight sits and where it is allowed to be touched.
| Hull data | What it changes |
|---|---|
| Light ship weight | Rated capacity, with margin for fuel, water and gear that may still be aboard. |
| Length overall and beam | Portal clear width, machine length, and the swept path in the yard. |
| Draft and keel depth | Hoist height and the depth the slings must reach below the waterline or the keel block. |
| Hull form | Sling positions, sling length per point, and whether a spreader or a hull-shaped frame is needed. |
| Hull material | Contact pressure limits: a GRP hull, a timber hull and a steel hull do not accept the same sling load. |
| Centre of gravity | Sling load sharing and the stability case during travel. |
| Blocking plan | Clearance under the keel at set-down, and the height the machine must hold while blocks go in. |
Two hull types cause most of the specification work. A sailing yacht with a deep fin keel cannot be set down on its keel, so the slings and the blocks have to hold it while the keel hangs free. A catamaran has two hulls and a wide bridge deck, so the slings pass under the hulls rather than across a single keel line, and the load is shared between four contact areas instead of two.
What "capacity" means on a travel lift
The rated capacity is the maximum lifting load, quoted for the machine as configured. It is not the maximum boat length, and it is not a figure that can be compared between two brochures without the sling arrangement.
- Rated capacity covers the vessel plus anything aboard. A hull lifted with fuel and water still in the tanks is a heavier lift than the same hull as delivered.
- Sling load is the number that matters to the hull. Each sling carries a share of the total, and the builder's sling plan sets the maximum allowed at each position.
- Duty class reflects how often the machine works. A marina that lifts fifty boats in a spring weekend and little else is a different duty from a yard that lifts daily, all year.
- Hoist height and speed decide cycle time on a busy slipway, and the height needed to clear a transport trailer or a storage cradle.
We publish the 200 t and 1,000 t builds in the case library, and the largest travel lift on the specification table is 1,200 t with an 18.8 × 21 m span and base. Those are real configurations, not a capacity ladder — each one was built for a hull size and a site.
Slings and hull support
The slings are the only part of the machine that touches the boat, and they are where damage claims originate.
- Wide webbing spreads the load. The contact pressure on the hull is a function of sling width and sling load, not of the machine's capacity.
- Position is set by the hull. Slings go where the structure can take them — under engine beds, bulkheads or designated sling marks, never at an arbitrary point along the length.
- Length is adjusted per point. A hull that is deeper aft needs a longer sling there; if all slings are the same length, the boat hangs out of level and the load shifts.
- Protection is replaceable. Pads, sleeves and spreader bars are consumables. Replacing them is cheap; repairing a deflected hull is not.
- Load monitoring on each sling, or on the hoist, turns a judgement call into a number the operator can see.
Ask the naval architect or the builder for the sling plan before the machine is specified. If no plan exists — common with older or one-off hulls — the yard's own lifting procedure and the surveyor's advice should set the positions, and the machine is then configured around them.
Slipway, quay and water
The lift happens at the water's edge, so the site conditions matter as much as the hull.
- Approach and apron. The machine has to reach the hull with the legs on sound ground, often on a slipway apron that slopes into the water.
- Gradient. A sloped apron changes the machine's level and the sling geometry. It also changes the wheel loads and the braking case.
- Water depth and tide. The slings must pass under the hull at the state of tide the lift actually happens in, not at the depth on the chart.
- Berth layout. Mooring lines, pontoons, fenders and neighbouring vessels all restrict how close the legs can come.
- Salt water and corrosion. Machines working at the water's edge need a coating, fastener and electrical specification that reflects it.
Where the site has a hoist dock or a slipway rail system, the machine can be configured to work with it rather than instead of it. That is a layout decision, and it is cheaper to settle before the machine is ordered than after the apron is poured.
Yard, storage and route
Once the boat is out of the water, the machine becomes a yard vehicle carrying a hull that is wider than its own track in many cases.
- Storage blocks and cradles have to be ready before the lift, and positioned where the machine can lower the hull onto them without a second move.
- Turning envelope is set by the hull, not the machine. A long yacht overhangs the portal on both ends in a tight turn.
- Ground bearing — the loaded wheel load goes into the quay or hardstanding, and marina pavements are often thinner than a shipyard slab.
- Overhead clearance along the whole route: cables, lighting, roof structure and the mast of a sailing yacht, which may have to be unstepped first.
- Wash-down and work areas are usually where the hull is set down, so the route has to reach them without crossing public access.
Drive, steering and control
Travel lifts are slow machines by design — the load is suspended and the ground is often wet.
- Diesel remains common for outdoor yards; electric suits covered yards and sites with emissions limits. Hybrid options exist where fuel burn and noise matter.
- All-wheel drive and crab steering let the machine approach a berth sideways and place a hull in a tight row.
- Remote control is used where the operator needs to see the sling positions or the keel clearance directly rather than through a cab window.
- Load cells and a display in the cab turn sling load sharing into something the operator can act on.
Safety and control
- Nobody under the hull. The exclusion zone is the whole area beneath the suspended vessel and the swept path of the machine.
- Slings checked before each lift. Webbing wears, pads move, and a sling that has been in salt water needs inspection as a matter of routine.
- Wind. A hull is a large sail. Above the yard's wind limit, the lift waits — that limit belongs in the operating procedure, not in the operator's judgement alone.
- Load and limit monitoring. Overload protection, hoist limits and travel interlocks are standard on this class of machine.
- Emergency lowering. A hull suspended over water or over blocks needs a controlled way down if power is lost.
Standards and documentation
Travel lifts are documented against the same lifting-machine standards as other portal machines:
- ISO 4301-1 and ISO 4301-5 — classification by duty.
- EN 15011 — bridge and gantry cranes, which covers the structural approach for the portal.
- IEC 60204-32 — electrical equipment of hoisting machines.
- ISO 12488-1 — tolerances for wheels and travel tracks.
Standards are cited by number only; the edition that applies to a contract is confirmed with the drawing package. Where a site has its own insurance or classification requirements, those are added to the documentation list at the technical review rather than assumed.
Not only boats
The same portal, slings and hoist are used for other heavy loads that cannot be lifted by their edges: industrial modules, tanks, and large precast units. The difference is in the sling plan and the contact protection, not in the machine concept.
Motor yachts
Deep hulls with a long keel line, where sling position and hull protection set the configuration.
Sailing hulls and timber
Fin keels that must hang free, and timber hulls that accept less contact pressure than GRP.
Yard moves
From the slipway to the wash pad, the blocks or the transport trailer — usually the longest part of the cycle.
Heavy modules
Tanks, plant modules and precast units handled on slings or a frame instead of a spreader.
What to send with an enquiry
Six items are enough for a first configuration:
- Hull type, length overall, beam, draft and light ship weight — plus the heaviest vessel the yard expects.
- Hull material and the sling plan, or the yard's own lifting procedure if there is no plan.
- A site plan showing the slipway or hoist dock, the apron, the storage area and the route between them.
- Gradient and water depth at the lift point, and the tide range.
- Ground information for the apron and the yard: surface, slab or pavement build-up, and any structural drawing.
- Lifts per year and the peak season pattern, so duty class and drive can be set against the real workload.
Photographs of the slipway and of a typical hull on the blocks are often more useful than a drawing, because they show the constraints the site plan leaves out.
Travel lift FAQ
What is the difference between a travel lift and a straddle carrier?
Both are portal machines that carry a load between their legs. A straddle carrier is built around containers, precast or steel; a travel lift is built around hulls, with slings, hoist height and a beam sized for a boat. The types page compares the families.
Can a travel lift lift a boat with a fin keel?
Yes. The hull is carried on slings with the keel hanging free, and the machine holds it high enough for blocks to go under the hull. The sling positions come from the builder or the surveyor, not from the machine supplier.
How do you decide between 200 t and a larger machine?
By the heaviest hull the yard expects, with margin for fuel, water and gear, plus the beam and draft of that hull. Buying for the average boat rather than the heaviest one is the most common specification error we see.
Does the machine work in salt water?
It works at the water's edge, and the specification reflects that: coating system, fasteners, electrical protection and inspection intervals. Slings and pads are consumables and are inspected as part of the lift routine.
What ground does a travel lift need?
The apron and the yard route must carry the loaded wheel loads — we return those per configuration, loaded and unladen, so the quay or pavement can be checked by a structural engineer. A marina pavement is often thinner than a shipyard slab.
Can the same machine handle boats and heavy modules?
Often yes, with a different sling plan and contact protection. Say so at the start, because the duty mix affects the classification and the attachment set.